Peri-implant Fractures Following Hook Plate Fixation for Unstable Distal Clavicle Fractures

Abstract

Clavicle hook plate is a common implant for treating distal clavicle fracture. Although high bone union rate and good functional outcome have been reported, so have several complications, such as osteolysis and fracture of the acromion, loss reduction, hook impingement, and rotator cuff tear. Peri-implant fracture over the medial side of the hook plate is a rare complication. Sporadic cases have been reported, and most of them have had no history of trauma. Between June 2015 and August 2018, 7 patients treated for distal clavicle fracture with a 3.5-mm locking compression hook plate with no history of trauma experienced peri-implant fracture of the medial clavicle. This complication occurred at a mean of 29 days. The incidence rate was 9.8%. Peri-implant fracture following hook plate fixation for distal clavicle fracture was not rare. Small hook angle, prolonged retention of the implant, an eccentric medial screw, high plate screw density, and small clavicle diameter may be risk factors for peri-implant fracture. Regarding treatment, 2 patients chose fracture revision with a distal clavicle locking plate and 5 patients chose conservative treatment. All patients achieved bone union at fracture sites. Surgical and conservative management of peri-implant fracture can achieve good functional outcome. [ Orthopedics . 2020;43(5);e359–e363.]

Risk factors for clavicular midshaft fractures after hook plate fixation for the treatment of Neer type II clavicular fractures

“…However, several studies have revealed a lower complication rate and lower stress on the clavicular midshaft when the hook or plate is bent. 14,17,18 In the current study, bending of the hook plate had a greater effect on decreasing the rate of occurrence of midshaft fractures among elderly than young patients. Although the effect was not statistically significant, it seems reasonable that bending of the hook plate should be encouraged during surgery, especially for elderly patients.…”

“…14 In a clinical study published in 2020, Ni et al. 14 demonstrated that the type of the most medial screw did not significantly influence the incidence of postoperative clavicular midshaft fractures (cortical screw: 8.3% vs. locking screw: 13.3%).…”

“…To the best of our knowledge, few studies have investigated potential risk factors for clavicular midshaft fractures after hook plate fixation in the treatment of Neer type II clavicular fractures. 13–15…”

“…2 However, clavicular midshaft fractures located on another stress concentration point are rarely reported because of their lower incidence (1.3%-9.8%). 6,13,14 One study showed that compared with patients without this complication treated with a hook plate, patients with midshaft fractures had worse shoulder functional outcomes and worse relationships with surgeons. 15 Surgeons should investigate the risk factors for this complication to lower the incidence of clavicular midshaft fractures after hook plate fixation and thus improve functional outcomes and relationships.…”

“…To the best of our knowledge, few studies have investigated potential risk factors for clavicular midshaft fractures after hook plate fixation in the treatment of Neer type II clavicular fractures. [13][14][15] This retrospective observational study was performed to analyze potential risk factors for this rare complication. We hypothesized that patients of advanced age, treated with hook plates not bent during surgery, a shorter plate, a plate with less depth, and an implanted locking screw at the most medial hole might have higher rates of postoperative clavicular midshaft fractures.…”